If you are looking for the "ultima version" (latest version) to simply documentaries, use the official website and install it as a PWA via your browser for the most up-to-date library. If your goal is to download for offline viewing, skip the official apps and use JDownloader 2 on your PC. DocumaniaTV - Free download and install on Windows

The Last Version

Si después de leer esto prefieres evitar complicaciones, existen alternativas 100% legales para descargar documentales: